When I bought my MV-100 I researched the preamp question and found, that for stealthing, I only had a couple of options. The MV-100, the Sonosax SX-M2, or the Aerco MP-2. (There was also a French-made EAA PS-P2, but it was really expensive and I wondered about parts availibility.) I settled on the Beyer because it was cheaper than the Sonosax. Plus, I could never find a photo of the Aerco, and I wasn't going to buy something sight unseen, even though I really liked the sound of the MP-2.
Right now I really can't afford to replace it with anything, though it's fun to think about. (I think I mentioned in a previous post that I actually had purchased a Lunatec V2, but traded it back for a DA-P1 because I couldn't stealth with it. [The unit was a little large but manageable, but the required cables+battery pack was too much gear.])